1. Field of the Invention
The present invention relates to a measuring mechanism for an assembled or a packaged BGA (Ball Grid Array)-IC, particularly to a measuring mechanism for measuring a packaged BGA-IC and the package of the BGA-IC capable of facilitating and assuring contact between a soldering ball and a contact seat for a BGA, and of shortening measuring time when the package of the BGA-IC and packaged BGA-IC are measured. The measurement of both the packaged BGA-IC and the package of the BGA-IC is hereinafter defined as the measurement of the BGA-IC.
2. Prior Art
In the conventional technique, a measuring mechanism for testing or measuring a BGA-IC has an arrangement, for example, as shown in FIG. 4(A) and 4(B).
In these figures, the measuring mechanism comprises, a substrate 60 composed of a contact seat 61 for contacting a soldering ball 71 of a BGA-IC 70 (hereinafter referred to as BGA contact seat 61), signal connection patterns 62 and 64, a signal connection through hole 63, and a measuring contact seat 65 for connecting to a tester, not shown.
The BGA contact seat 61 is formed on the substrate 60 and it is circular and flat.
The BGA contact seat 61 is connected to the measuring contact seat 65, which is positioned at the tester side and opposite to the BGA contact seat 61, through the signal connection pattern 62, the signal connection through hole 63 and the signal connection pattern 64. The measuring contact seat 65 is connected to a circuit such as a pin electronic circuit at the tester side.
With such an arrangement, when the BGA-IC 70 is tested, the soldering ball 71 of the BGA-IC 70 is forced to contact the BGA contact seat 61 so that the assembled BGA-IC 70 can be tested in its electric characteristics.
However, in the conventional measuring mechanism for a BGA-IC, the surface of the BGA contact seat 61 formed on the substrate 60 is flat. On the other hand, the surface of the soldering ball 71 of the BGA-IC 70 is spherical. Accordingly, the soldering ball 71 and the BGA contact seat 61 contact each other at a point, namely, they contact each other in a point contact mode (FIG. 4(B)).
That is, as shown in FIG. 4(B), the soldering ball 71 contacts the BGA contact seat 61 at a point 71A.
Accordingly, if a foreign matter 80 is sandwiched between the soldering ball 71 and the BGA contact seat 61 as shown in FIG. 5, the BGA contact seat 61 and the soldering ball 71 do not normally contact each other, so that inferior contact occurs, which makes it difficult to measure the BGA-IC 70.
That is, since the soldering ball 71 contact the BGA contact seat 61 at the point 71A alone (FIG. 4(B)), it can not contact the BGA contact seat 61 in other portions if the foreign matter 80 is sandwiched between the soldering ball 71 and the BGA contact seat 61, which makes them inferior in contact.
It is an object of the invention to provide a measuring mechanism for a BGA-IC capable of assuring and facilitating the contact between a soldering ball of a BGA-IC and a BGA contact seat even if a foreign matter is sandwiched therebetween, and also capable of saving time involved in checking of the recontact therebetween, thereby shortening measuring time.
To achieve the above object, the invention comprises a substrate 30 including a BGA contact seat 10 which is embedded therein and has a conical contact surface 10A, and is connected to a tester, and a BGA-IC 40 having a soldering ball 41 wherein the soldering ball 41 contacts the conical contact surface 10A of the BGA contact seat 10 when the BGA-IC 40 is tested.
With such an arrangement, since the conical contact surface 10A of the BGA contact seat 10 is conical (FIGS. 1, 2 and 3), the entire outer periphery 41A of the soldering ball 41 of the BGA-IC 40 can contact the BGA contact seat 10 so that they can contact each other in a line contact mode, and hence even if a foreign matter 50 is sandwiched between the soldering ball 41 and the BGA contact seat 10, they can contact each other at the other portions other than the portion where the foreign matter 50 is sandwiched therebetween.
Further, since the contact between the soldering ball 41 and the BGA contact seat 10 can be facilitated and assured compared in the point contact mode at the point 71A as explained with reference to FIGS. 4 and 5, it is not necessary to check the recontact therebetween, and hence measuring time can be shortened by the time involved in checking the recontact therebetween.
That is, since the conical contact surface 10A of the BGA contact seat 10 is conical, the conical contact surface 10A can contact the BGA-IC 40 at any part of the conical contact surface 10A even if the foreign matter 50 is sandwiched between the soldering ball 41 and the BGA contact seat 10, and hence the contact therebetween can be facilitated and assured, thereby saving time involved in checking the recontact therebetween to shorten the measuring time.